1. Field of the Invention
The present invention generally relates to an optical imaging lens set and an electronic device which includes such optical imaging lens set. Specifically speaking, the present invention is directed to an optical imaging lens set of five lens elements and an electronic device which includes such optical imaging lens set of five lens elements.
2. Description of the Prior Art
In recent years, the popularity of mobile phones and digital cameras makes photography modules (including optical imaging lens set, holder and sensor, etc) well developed. Mobile phones and digital cameras become lighter and thinner, so the miniaturization demands of photography modules get higher and higher. As the charge coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) technologies advance, the size of the photography modules can be shrunk too, but these photography modules still need to maintain good imaging quality. The optical imaging lens set of five lens element has been developed.
U.S. Pat. No. 7,480,105, U.S. Pat. No. 7,639,432, U.S. Pat. No. 7,486,449 and U.S. Pat. No. 7,684,127 are disclosed an optical imaging lens set of five lens elements respectively. However, in U.S. Pat. No. 7,480,105 and U.S. Pat. No. 7,639,432, the first lens element and the second lens element have negative refractive power and with positive refractive power respectively; in U.S. Pat. No. 7,486,449 and U.S. Pat. No. 7,684,127, both the first lens element and the second lens element have negative refractive power. This arrangement cannot achieve good optical performance. Besides, in those four patents, the total length of the optical imaging lens set is between 1018 mm, and the size of the optical imaging lens set is too big to satisfy the specification requirements of consumer electronics products.
In addition, U.S. Pat. No. 8,233,224, U.S. Pat. No. 8,363,337 and U.S. Pat. No. 8,000,030 further disclosed an optical imaging lens set of five lens elements respectively. Even though in those patents, the first lens element and the second lens element have positive refractive power and negative refractive power respectively (which is a better arrangement), the configuration of the third to fifth lens elements cannot improve the aberration and shorten the total length simultaneously. Therefore, in consideration of the premise of image quality, these optical imaging lens sets still cannot be effectively shortened. For example, parts of the optical imaging lens set are still about 6 mm, which requires further improvement.
Therefore, how to reduce the total length of a photographic device, but still maintain good optical performance, is an important research objective.